A servo motor (a.k.a. simply a “servo”) is a device having a rotatable output shaft. The output shaft can typically be positioned to specific angular positions in accordance with a coded signal received by the servo. It is common that a particular angular position will be maintained as long as a corresponding coded signal exists on an input line. If the coded signal changes, the angular position of the shaft will change accordingly. Control circuits and a potentiometer are typically included within the servo motor casing and are functionally connected to the output shaft. Through the potentiometer (e.g., a variable resistor), the control circuitry is able to monitor the angle of the output shaft. If the shaft is at the correct angle, the motor actuates no further changes. If the shaft is not at the correct angle, the motor is actuated in an appropriate direction until the angle is correct.
There are different types of servos that include output shafts having varying rotational and torque capabilities. For example, the rotational and/or torque capability of an industrial servo is typically less restricted than that of a hobby servo. That being said, hobby servos are generally available commercially at a cost that is much less than that associated with industrial servos.
Because hobby servos are relatively small and inexpensive, they are popular within the hobby-mechanical industry for applications such as, but by no means limited to, hobby robotic applications and radio-controlled models (cars, planes, boats, etc.). One example of a hobby servo is the Futaba S-148 available from Futaba Corporation of America located in Schaumburg, Ill.